1. Field of the Invention
The invention relates to electronics packaging technology and in particular to an exposed-pad quad flat package (QFP) having exposed common electrode bars and an electronic device including the package.
2. Description of the Related Art
Driven by miniaturization of highly integrated and advanced semiconductor devices, requirement for higher density packaging has increased. For this purpose, semiconductor manufacturers must provide semiconductor packages having thinner profiles. In the highly integrated and advanced semiconductor devices, to process signals at a high speeds, the heat developed in the dies and the inductance in package cannot be ignored. Thus, heat dissipation and lowering inductance are two important tasks for semiconductor manufacturers. The heat produced from die can be eliminated from the package by providing a thermal path. Additionally, the inductance can be lowered from the package by increasing the number of power or ground terminals.
In order to meet the above demand, exposed-pad quad flat package (QFP) has been developed for practical use. In the exposed-pad QFP, closely spaced leads along the edges of a die pad having a semiconductor die attached thereon are used for electrical connection between the die and the external circuits. Moreover, the bottom surface of the die pad is exposed from the package body and can be boned to a print circuit board (PCB) so that the heat from the die can be effectively dissipated.
However, high speed operation and high performance semiconductor devices require more signal processing terminals (leads), thus leading to fabrication difficulties with QFP. To solve this problem, ball grid array (BGA) packaging has been developed. In the BGA package, electrical contact balls for connecting the die to the external circuit are formed on the bottom surface of the package. Accordingly, compared to QFP, more electrical contact points with greater spacing therebetween can be accomplished. Unfortunately, BGA packaging is not cost-effective compared to QFP and the fabrication of a BGA package is more complicated than a QFP.